This is the opening 5 minutes of Left 4 Dead and what can I say? You should watch it, it's very entertaining, very well acted, and would do the zombie genre proud if it were a film. Lots of guns blazing and some NSFW language if you're watching around others. Left 4 Dead: Opening Cinematic [Gametrailers, thanks Breadtruck, who also advises the scene is downloadable via Steam]
Last I checked, Alex was at least partially black, Chell has some Asian thing going, and the girl in L4D looks like a standard brunette Caucasian. In other words, to me, they all come across as ethnically diverse. Are they all attractive, fit, and around the same height, though? Yes. I can agree with that.